China has signaled a frostier approach to North Korea, with the Bank of China cutting ties with Pyongyang’s primary foreign-exchange bank. The WSJ’s Lingling Wei tells Deborah Kan why Beijing is finally distancing itself from its unruly neighbor.

This transcript has been automatically generated and may not be 100% accurate.

... the the ... eyes with all three as wine foreign exchange think I'd ever con joining me now it is Lingling Wei reporter from Beijing ... Lingling China is North Korea's really um only significant ally left in the world so would you say ... that this marks a big change in its approach to the relationship ... I'm Deborah ... on this move by and turn down certain the parents on diplomatic ... significance on even as you said to their doctrine dynasty only in long ... on time ally of the Norse Korea ... on onthe on the hands of ... pressure has been building on China a big change ... from boosting U S ... jobs sectors in the Chinese public ... onto the tougher race Knauss Korea ... given their increasingly the maintenance I the caveat so on this is really the first time that the Chinese government control it ... and see that Hess announced taken measures to ... ALM distance itself from an Oscar an entity taken from the Karissa on diplomatic significance here ... on the other hand dyed profitable bit too early to say that now ... marks a change in how China is handling ... its relationship with its longtime ally ... of the croissant as you know China's long standing ... policy when it comes to an on screen there ... is still to maintain on Kate relationships ... with sound was replaced as Korea ... and on a daily Al hast rejected any cost to ... ALM ... no pain ... tougher on all of its neighbor ... they said oh wait and see ... that re victory North Korea and time adults is reported to be around one point three billion dollars for the first three months of this year ... what does cutting off ties um ... with the foreign exchange bank of Nenad for trade ... aam has a very good question as inflated balance of tipping the scales say it ... is not about it on however ... this on the screen that foreign trade and the furnace Korea ... on is virtually the country's ... central bank and on is the primary foreign exchange bank on for the country ... so I can own a in ... China it's on the largest ... foreign exchange bank in China so aam it probably means that I ... basically a lot of fun aspects related transactions on bed to on the screen bank ... is trying to on the dot com you know will be accepted an implied by its counterparty ... of which is a band of China ... on ... Nov which ... could make it harder ... on for most Korea to on a nosh ... move money I in and out of the country ... the pm The about Lingling the timing of this new baby given the fact that ... in relation to create a North Korea and the U S are especially IDC right now ... aam I did that had much to do with it and was the U S involvement putting pressure on China ... I'd to take a more stern approach with Pyongyang ... as a contestant on this mean for me I have seen ... an enticement reported a story ... on Washington deftly Comcast I'd talk to stop this the Wayne ... Bennett ... of the curse on I mean this guy or the charities factory when she was seen big chain ... last month's he gets in on race issues ... involving the Start screen that we stop was he's Chinese counterparties ... up and end up tying on China to make any public announcement no comment on the issue ... so that I mean it really iam is you know it's interesting because ... the move taken by China on its actually know followed a visit by the U S Treasury Secretary to Beijing ... it certainly not good news for North Korea to now has limited ... opportunities for trade in for spice ... thanks Fran much Lingling joining us from Beijing for more on that story indebted Des beest dot com I'm Deborah con ...